It has been reported that the gastrointestinal ulcers may be caused by a excessive secretion of acids such as hydrochloride acid or pepsin as well as by an action of anti-inflammatory agents such as indomethacin, toxic chemicals, pathogenic virus or toxic microorganisms. In particular, it had been reported that H.sup.+ /K.sup.+ ATPase, an enzyme which plays an important role during the last step of the acid secretion in stomach cell affects the gastric acidity (Am. J. Physiol., 1983, 245, G589, J. Biol. Chem., 1976, 251, 7690). Therefore, if a compound has an inhibitory activity against the enzyme so that it can be used to suppress gastric acid secretion and treat gastric ulcers.
JP 82-134417A and KR 91-7679A disclose some thiazole derivatives having anti-ulcer activity, and JP 81-5538A and U.S. Pat. No. 4,283,408 teach thiazole derivatives having an activity of suppressing the secretion of gastric juices.
However, there has been still a need to develop agents which are capable of reinforcing various defensive factors against the above described factors causing gastrointestinal ulcers.
The present inventors made extensive researches to provide novel compounds which can effectively inhibit H.sup.+ /K.sup.+ ATPase. And a result thereof, they found out that the compounds represented by the general formula (I) given below showed not only a potent inhibitory activity against H.sup.+ /K.sup.+ ATPase so that they can suppress the secretion of the gastric juices but also a significant cell protecting activity.